Though the Kansas City, Missouri, rapper is now in his early 40s, his music has lost little of the manic energy he flashed when he first made his debut more than two decades ago. Words still fire from him in short, clipped bursts (note the name), and his songs are still fueled by a host of internal and external demons, touching on subjects that range from addiction to the ills of war (he penned “The Noose,” for one, after visiting with wounded veterans at California’s Camp Pendleton).

While Tech, born Aaron Yates, has never been embraced by the mainstream — his music has always been too intense for radio and his live show too out-there (he used to perform wearing face paint and hospital scrubs) for most concertgoers — he’s still managed to carve out a rabid following the old-fashioned way: through relentless touring and a craftsman’s commitment to quality.